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An Update on Chlorpyrifos for Mosquito Control

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EPA announces decision that bans the use of chlorpyrifos on food

On Wednesday, August 18, 2021, the EPA made a final decision to revoke all tolerances for Chlorpyrifos on food production, meaning any products containing Chlorpyrifos may no longer be applied on crops.  The EPA indicated a 6-month timeline for implementing this ban for agricultural uses.  See the full EPA announcement here.

Non-agricultural uses, including mosquito control, are not covered by this decision. Mosquito control programs will continue to have access to this active ingredient for resistance management. 

Clarke reiterates our previous decision, announced in August 2020, to sunset all chlorpyrifos formulations in our proprietary product portfolio. Our MosquitoMist and MosquitoMaster products will no longer be commercially available in the U.S. after December 31, 2022.  We will continue to maintain the necessary state registrations for an interim period to allow customers holding inventory of these formulations to use the material.

We all recognize the need for new modes of action in mosquito control has never been more paramount than it is today.  Clarke continues racing to prepare a new mode of action adulticide for public health use that addresses the growing challenge of pyrethroid resistance and waning public acceptance for organophosphate chemistries.

Our decision in 2020 to sunset our Chlorpyrifos products was not an easy one, but EPA’s decision reinforces its merits.  We are committed to working on product transition plans for our customers that use our Chlorpyrifos formulations, while continuing to align the development of new mosquito control products and solutions with our customers’ needs: public health tools that meet public preference.

Update: Since the original publishing of these announcements, Clarke has extended the timeline for its voluntary chlorpyrifos sunset. This decision was made to allow customers access to these products for rotational use and resistance management, while Clarke continues its work to bring additional resistance management tools to the public health mosquito control market.